fix(ibc): dynamic block-time-aware packet timeout with p95 estimation and recalibration

Cargo.toml

@@ -81,6 +81,10 @@ path = "tests/pg_pool_health_probe_test.rs"
 name = "relay_endpoint_cache_poisoning_test"
 path = "tests/network/relay_endpoint_cache_poisoning_test.rs"
 
+[[test]]
+name = "ibc_packet_timeout_test"
+path = "tests/cross_chain/ibc_packet_timeout_test.rs"
+
 # ── Lint policy ──────────────────────────────────────────────────────────────
 # Enforced via `cargo clippy -- -D warnings` in CI. The lints below are the
 # style/pedantic ones we deliberately do not churn on:

src/cross_chain/ibc/mod.rs

@@ -0,0 +1,33 @@
+//! IBC packet commitment timeouts across variable block-time chains
+//! (issue #138).
+//!
+//! An IBC packet carries a `timeout_height` denominated in the *destination*
+//! chain's blocks. Deriving that height from a fixed, assumed block time
+//! mis-times every packet the moment the destination chain's real block time
+//! departs from the assumption — and it departs constantly, both because chains
+//! differ from one another and because a single chain's block time moves under
+//! load.
+//!
+//! * [`block_time_estimator`] — the per-chain sliding window of block-time
+//!   samples and the three statistics derived from it (mean, p95, EMA).
+//! * [`packet_timeout`] — the timeout-height formula, its unit derivation, and
+//!   the cold-start safety margin.
+//! * [`packet_relayer`] — in-flight packet tracking, misestimation
+//!   classification, the recalibration trigger, and the observability events.
+//!
+//! Samples reach the estimator from the existing header-sync pipeline via
+//! [`crate::cross_chain::ConnectedChain::observe_header`]; there is no second
+//! header path.
+//!
+//! Like the rest of [`crate::cross_chain`], everything here is deterministic,
+//! integer-only, and dependency-free so it compiles to WASM (`no_std`) and is
+//! shared verbatim by off-chain relayers.
+
+#[path = "block-time-estimator.rs"]
+pub mod block_time_estimator;
+
+#[path = "packet-timeout.rs"]
+pub mod packet_timeout;
+
+#[path = "packet-relayer.rs"]
+pub mod packet_relayer;